So goes the rollicking but inconclusive — so far — Republican presidential contest, as it moves from small ball to big time in Florida for a Jan. 31 primary in which some 4 million state Republicans are eligible to vote.

Perspective? More Florida Republicans have already cast early ballots than all New Hampshire votes tallied for the top three finishers in that state's Jan. 10 GOP primary, about 197,000.

"Preseason is over," says Susan MacManus, a state political expert at the University of South Florida. "It's a whole new game."

And in Florida, much of that game will be played out in the Interstate 4 corridor, which extends coast to coast in the center of the state, from Tampa to Daytona Beach.

"As we like to say, the I-4 corridor is the highway to political heaven for presidential candidates," MacManus says. "It's the swing part of the swing state."

Nearly half of Florida's registered Republicans — there are 4,071,049 statewide — live in the corridor, a dream for demographers and those engaged in the business of focus groups and product testing.

It encompasses rural, urban and suburban areas, and embraces significant racial, ethnic and religious diversity, as well as a wide age range among registered voters.

It's here, in Orlando, where the new sort-of front-runner Gingrich, the former House speaker who just clobbered Romney in the South Carolina primary, opened a campaign headquarters recently and plans to spend primary night.

And where Romney, the former Massachusetts governor who won in New Hampshire and is seeking to reclaim his inevitability crown, headed Sunday afternoon for an event near Daytona Beach.

But just how they, and Iowa caucus winner Rick Santorum (Texas Rep. Ron Paul has set his sights beyond Florida), make their case here to GOP voters, whose preferences have shifted like sands on their famous beaches, is only beginning to jell.

Scrap Previous Polls

First, ignore previous Florida polls, politicos advise. A current state poll average compiled by RealClearPolitics.org shows Romney with a lead of more than 10 percentage points over Gingrich.

That, however, includes surveys taken before the stunning South Carolina results were in, and largely before Romney began to be damaged by criticism of his work in private equity at Bain Capital and his resistance to releasing his tax returns.

Under pressure, Romney on Sunday morning announced on Fox News that he'll release his 2010 returns, as well as a summary of his 2011 returns.

Florida Republicans have also proven flagrantly fickle this season. Gingrich in late November and early December topped state polls with support from up to 48 percent of those surveyed, before he took a nosedive.

Before businessman Herman Cain dropped out of the race, he had once run strong second to Romney and was a real Florida Tea Party favorite.

Texas Gov. Rick Perry, who dropped out of the race last week, sat comfortably atop the polls in late September before imploding.

Lew Oliver, chairman of the Republican Party in Orange County, which includes Orlando, suggests that national polls provide a better barometer of what's happening politically in the Sunshine State.

"Florida reflects the national numbers," he says. "It's a pretty representative sample."

Both he and MacManus say they are more interested in what national polls expected in coming days will show might happen in potential match-ups between President Obama and Romney, and Obama and Gingrich. Romney in previous polls has typically run close to even with Obama, Gingrich about 10 points behind.

That indication of "electability," MacManus suggests, as well as how candidates fare in Monday's debate in Tampa, will be key to where Florida Republicans place their presidential bets next week.

The wild card? Oliver, the Orange County GOP chairman, says it's Santorum. The former Pennsylvania senator has insisted he's in the race at least through Florida. But if he changes his mind and gets out before the primary, Oliver suggests, he could play kingmaker.

"And he wouldn't even have to endorse," he said.

If Santorum drops out, some predict, Gingrich benefits hugely.

Strategies Emerge

Bertica Cabrera Morris, a senior Romney adviser who lives in Orlando, envisions a three-pronged campaign to take the shine off Gingrich in Florida, and quickly.

Romney and his surrogates are expected to provide a stronger defense of capitalism and the former Massachusetts governor's business experience, contrasting it with Gingrich's years in Washington.

They expect to hit the former House speaker hard on personal character issues, and to press him to release information on what he did to earn $1.6 million from mortgage giant Freddie Mac. That includes an event on Monday when former Minnesota Gov. Tim Pawlenty and Will Weatherford, the speaker designate of the Florida House, hold a conference call with reporters to discuss Gingrich's work at Freddie Mac.

Monday morning, Romney himself called Gingrich "highly erratic," and told reporters: "He's gone from pillar to post almost like a pinball machine."

"I didn't focus attention about the women thing before," said Cabrera Morris, a Cuba-born businesswoman and married mother of five who coordinated Florida Sen. Marco Rubio's I-4 election effort and worked for former Gov. Jeb Bush. "But now, I will tell that message to a lot of people."

One of the thrice-married Gingrich's ex-wives, in an interview last week with ABC, alleged that while her husband was carrying on an affair with his current wife, Callista, he requested an open marriage.

Romney brings to the Florida contest an extensive organization and money to compete in an expensive media landscape of nearly a dozen markets.

"We have been ready for this for a long time," Cabrera Morris says. "We've been going on this for six months and have an organization in place."

Romney campaign ads, as well as those from the superPAC supporting him, including as many critical of Gingrich as rosy about Romney, have been flooding television airwaves for weeks. No other candidate has yet been on the air.

He'll have a fundraiser Wednesday in Orlando, Cabrera Morris says, and plans a speech in Miami's Freedom Tower, a memorial to Cuban immigration.

"We're not going to be able to compete dollar for dollar with Mitt Romney," said Miranda, who like many of Gingrich's staff and supporters here was with Herman Cain earlier on, in Miranda's case as central Florida field representative. "We'll rely on earned media and debates."

Gingrich has shone in the debates, and many credit his South Carolina triumph with his forceful attack on the media during the debate two days before the Palmetto State contest.

Arthur Grimes, a retired New York City bus driver who now lives in Orange City, in the I-4 corridor, synthesized Gingrich's new appeal post-South Carolina: "What the hell is his name — Newt Gingrich. He's got a pair."

Miranda says Gingrich volunteers have also been reaching out to the large Hispanic evangelical community in the Orlando area, and the campaign hopes to capitalize on the Newt-is-tough-enough-to-beat-Obama theme in coming days.

"We've got him here in Florida for eight days before the primary," he said, "and we've got him in strategic areas."

The most strategic? There's Miami, and there's Jacksonville. But by almost any measure, it's the I-4 corridor and its melting-pot-America characteristics that may prove the most decisive strip of land in the nation when it comes to who will emerge as the GOP nominee at the party's August national convention in Tampa.

"Floridians," said Cabrera Morris, "don't care about what they do in South Carolina."